There are a number of applications for which it is desirable to inject eggs containing early avian embryos. For example, it may be desirable to deliver a substance to an early embryo, such as a blastoderm. To illustrate, it may be desirable in the poultry industry to manipulate an early embryo in ovo to introduce a foreign nucleic acid molecule (i.e., to create a transgenic bird) or to introduce a foreign cell(s) (i.e., to create a chimeric bird) into the developing embryo.
Likewise, improved methods of injecting eggs containing an early embryo may be used to remove samples from eggs, including samples of embryonic and extra-embryonic materials. Further, for other applications it may be desirable to insert a sensing device inside an egg containing an embryo to collect information therefrom.
Current methods of manipulating bird eggs containing early embryos may be undesirable because they may result in unacceptably low hatch rates. It has been suggested that depressed hatch rates are a result of the opening made in the egg shell, introduction of air bubbles into the egg, damage to the extra-embryonic membranes or to the embryo itself, or a combination of these factors.
Accordingly, there is a need in the art for improved methods of manipulating avian eggs containing early embryos.